Traditionally, PMUTs use either a bi- or unimorph structure. A unimorph structure consists of a single active layer of piezoelectric material sandwiched between two electrodes coupled with a passive bending layer. To transmit ultrasound, a voltage is applied across the electrodes, which induces a transverse stress in the piezoelectric layer via the inverse piezoelectric effect, resulting in an out-of-plane deflection which transmits an ultrasonic pressure wave into a gas or fluid. Similarly, when the PMUT is used as a receiver, the applied pressure results in out-of-plane bending and the generation of measurable charge via the direct piezoelectric effect. Bimorph structures utilize two piezoelectric layers between patterned electrodes and are typically driven differentially. Since these approaches only use a single piezoelectric material, the piezoelectric material constants (piezoelectric coefficients, dielectric constant, Young's modulus, etc.) of the chosen piezoelectric material are only optimized for a single mode of operation, i.e., transmitter or receiver. The inability to optimize the transducer's sensitivity for both transmitter and receiver modes results in significant reduction in the system performance for ultrasonic systems commonly used in medical imaging, ranging, non-destructive testing, ultrasonic data communication, and gesture recognition applications.